The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.
Application notesICC/IF: Use at a concentration of 10 µg/ml.
Note: ab67035 requires Protein A affinity purification prior to ICC/IF application.
WB: 1/500 - 1/1000. Detects a band of approximately 99 kDa (predicted molecular weight: 103 kDa).
Not yet tested in other applications.
Optimal dilutions/concentrations should be determined by the end user.
FunctionCore component of multiple cullin-RING-based E3 ubiquitin-protein ligase complexes which mediate the ubiquitination and subsequent proteasomal degradation of target proteins. The functional specificity of the E3 ubiquitin-protein ligase complex depends on the variable substrate recognition subunit. CUL4B may act within the complex as a scaffold protein, contributing to catalysis through positioning of the substrate and the ubiquitin-conjugating enzyme. Plays a role as part of the E3 ubiquitin-protein ligase complex in polyubiquitination of CDT1, histone H2A, histone H3 and histone H4 in response to radiation-induced DNA damage. Targeted to UV damaged chromatin by DDB2 and may be important for DNA repair and DNA replication. Required for ubiquitination of cyclin E, and consequently, normal G1 cell cycle progression. Regulates the mammalian target-of-rapamycin (mTOR) pathway involved in control of cell growth, size and metabolism. Specific CUL4B regulation of the mTORC1-mediated pathway is dependent upon 26S proteasome function and requires interaction between CUL4B and MLST8.
PathwayProtein modification; protein ubiquitination.
Involvement in diseaseDefects in CUL4B are the cause of mental retardation syndromic X-linked Cabezas type (MRXC) [MIM:300354]; also known as mental retardation syndromic X-linked type 15. A syndromic form of X-linked mental retardation characterized by severe intellectual deficit associated with short stature, craniofacial dysmorphism, small testes, muscle wasting in lower legs, kyphosis, joint hyperextensibility, pes cavus, small feet, and abnormalities of the toes. Additional neurologic manifestations include speech delay and impairment, tremor, seizures, gait ataxia, hyperactivity and decreased attention span.
Sequence similaritiesBelongs to the cullin family.
Post-translational modificationsNeddylated. Deneddylated via its interaction with the COP9 signalosome (CSN) complex.
Zou Y et al. Characterization of nuclear localization signal in the N terminus of CUL4B and its essential role in cyclin E degradation and cell cycle progression. J Biol Chem284:33320-32 (2009).
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